A cellulose composite of cellulose and a hydrophilic gum has been conventionally known to form cellulose colloid in an aqueous medium and show satisfactory suspension stability and is widely used in the fields of e.g., foods, medical products, cosmetics, paints, ceramics, resins, catalysts and other industrial products. Particularly, a cellulose composite is used, e.g., as a stabilizer such as a suspension stabilizer, an emulsification stabilizer and a thickening stabilizer, a texture imparting agent, a clouding agent, a whitening improver, a flowability improver, a polisher, an alternate material for a dietary fiber and a fat and oil. For example, in a beverage, e.g., calcium enriched milk, a cellulose composite is added for stabilizing suspension of high-gravity water-insoluble components like milk calcium and calcium carbonate.
To improve the suspension-stabilizing effect of a cellulose composite, various studies have been made.
Patent Literature 1 JP 7102113 A, discloses a water dispersible composite containing micro cellulose and carboxymethylcellulose sodium.
Patent Literature 2 JP 6335365 A, discloses a food composition containing a water dispersible composite formed of micro cellulose and carboxymethylcellulose sodium.
However, the cellulose composites described in Patent Literatures 1 and 2 had a problem in that the dispersion stabilizing performance in the presence of an acid and/or a salt is not sufficient, with the result that separation and aggregation occur when the cellulose composite is used in fruit juice beverages, lactobacillus beverages or liquid seasonings.
Patent Literature 3 JP 9003243 A, discloses a water dispersible composition containing micro cellulose and a specific carboxymethylcellulose sodium and a food composition containing the water dispersible composition. The water dispersible composition is described to show excellent suspension stability and emulsion stability under an acidic environment.
In the water dispersible composition described in Patent Literature 3, micro cellulose itself has satisfactory dispersion stability in fruit juice beverages, acidic beverages such as a lactobacillus beverage and salt-containing aqueous compositions such as seasonings including sauce and mop sauce. However, the water dispersible composition had a problem in that long-term storage stability, furthermore, suspension stability when a water-insoluble component such as a functional food material was added were insufficient, causing sedimentation and aggregation.
Patent Literature 4 JP 2008048604 A, describes a stabilizer containing water dispersible cellulose and a polysaccharide. Since the stabilizer contains micro fibrous cellulose stably suspended in water, it serves for fixing particles in an acidic or high salt concentration food and drink such as yogurt, fruit sauce and dressing, contributing to providing commercial products having good appearance. However, the micro fibrous cellulose described in Patent Literature 4 is formed of cellulose and psyllium seed gum in combination. This is not a composite and thus suspension stability was insufficient.
Patent Literature 5 JP 2009291081 A, describes a bacterial cellulose composite. The Patent Literature describes that the bacterial cellulose composite is used in various types of milk-containing beverages and stable acidic milk beverages can be produced since it is excellent in dispersion stability and suspension stability. The bacterial cellulose described in Patent Literature 5 has an extremely thin and long shape and thus the storage elastic modulus (G′) of a water dispersion becomes excessively high. As a result, it caused a problem that the texture (feeling in the throat) of a food and drink containing the bacterial cellulose becomes heavy. In addition, if the additive amount of the bacterial cellulose is reduced to control texture, a problem of aggregation with a component of a food and drink has occurred.